Many types of battery pack are in common use, some of the most common being rechargeable power supplies for portable equipment such as, for example, camcorders, mobile phones and notebook computers. Typically, such a pack comprises a battery of cells, a casing to protect and contain the cells, means for interconnecting the cells within the casing and conductors running from the interconnected cells to external terminations. The casing shape and termination placement my be such that it mates both electrically and physically with external equipment such as that exemplified above and, in the case of a rechargeable pack, a charger. Also included within the pack is a thermally sensitive circuit breaker which serves to disconnect the cells in the event of excessive cell temperatures.
Presently, it is being proposed to include some control or monitoring means within a battery pack. Such an arrangement might provide for charge current control during recharge, charge monitoring during discharge and charge (for a rechargeable pack), display of battery condition and possibly transmission of battery condition or other parameters to external equipment. Such arrangements are described in European Patent Application 92402955.6. In one such arrangement, the control means can be implemented using a micro-computer of the micro-controller type. Arrangements of this type are sometimes referred to as "intelligent battery packs".